Rotary tower crane

ABSTRACT

A rotary tower crane has a tower constructed from vertically aligned rectangular sections whose cross-sectional dimensions can be altered to provide a tower of small or large cross section, as required. Each tower section is formed from uniformly sized sidewall units which are detachably connected to form the sidewalls of the rectangular tower sections. The height or length of each sidewall unit is the height of each rectangular tower section. The width of each sidewall unit is equal to, or is some convenient fraction of, the width necessary to form the sidewalls of a crane tower having the minimum cross-sectional area desired. The width of the sides of the tower sections can be expanded to increase the cross-sectional area of the tower by increasing the number of sidewall units detachably fastened together to form the sidewalls of the tower sections.

ilnited States Patent Reich [4 Feb. 18, 1975 ROTARY TOWER CRANE {75] inventor: Elmar Reich, Biberach, Germany [73] Assignee: Hans Liebherr,Biberach/Riss,

Germany 22 Filed: June 14, 1973 21 Appl. No.: 369,971

[30] Foreign Application Priority Data Primary ExaminerR0bert B. Reeves Assistant Examiner-Francis J. Bartuska Attorney, Agent, or FirmEdward R. Weingram [57] ABSTRACT A rotary tower crane has a tower constructed from vertically aligned rectangular sections whose crosssectional dimensions can be altered to provide a tower of small or large cross section, as required. Each tower section is formed from uniformly sized sidewall units which are detachably connected to form the sidewalls of the rectangular tower sections. The height or length of each sidewall unit is the height of each rectangular tower section. The width of each sidewall unit is equal to, or is some convenient fraction of, the width necessary to form the sidewalls of a crane tower having the minimum cross-sectional area desired. The width of the sides of the tower sections can be expanded to increase the cross-sectional area of the tower by increasing the number of sidewall units detachably fastened together to form the sidewalls of the tower sections.

8 Claims, 3 Drawing Figures [56] References Cited UNITED STATES PATENTS 2,580,503 1/1952 Athy et al7 52/637 2,988,180 6/1961 Campbell et al... 3,407,559 10/1968 Durand 52/637 ll I l l l |L l' 7 l PATENTEU FEB] 8l975 SHEET 1 BF 2 1 ROTARY TOWER CRANE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to construction equipment and, more particularly, to rotary tower cranes having towers constructed from a plurality of detachable sections.

2. Description of the Prior Art There are two main types of rotary tower cranes. One type has a needle-type boom of variable inclination. The other, and more common, type has a horizontal boom with a crab movably mounted on the boom to move in the lengthwise direction of the boom. The tower of either type of crane can be mounted on an undercarriage adapted to travel on rails, or else is mounted in fixed position on a base. The boom is pivotable with respect to the tower, either being pivotally mounted to the head of the inner tower and/or the inner tower head being rotatably supported about the longitudinal axis of the outer tower.

If rotary tower cranes are constructed with a freestanding tower, i.e., without external lateral support for the tower, the maximum height of the tower will depend upon the size of the cross section of the tower. The longer the freestanding tower is to be, the larger the cross section of the tower must be, to provide stability and strength to the structure. For example, the cross-sectional dimensions of the tower for tower heights above 30 meters are no longer determined by the lifting capacity of the rotary tower crane, but instead are determined by the stability required to withstand lateral wind pressure.

To obtain maximum benefit of a tower crane, it is desirable to have the tower crane as close to the work area as possible. Consequently, it is desirable that the tower of the crane have the smallest possible cross section, namely, the cross section sufficient only to handle the desired lifting capacity of the rotary tower crane. However, in order to assure stability of such a narrow tower crane against lateral wind pressure, it is necessary to anchor the narrow tower to the building alongside which the rotary tower crane has been placed for operation, at one or more places along the length of the tower.

Anchoring the tower to the building is disadvantageous, however, because the anchoring devices required, as well as their installation between the rotary tower crane and the building, are relatively costly. Therefore, it is considered preferable to make the towers freestanding, where practicable, in order to avoid having to use the anchoring procedures described above. Accordingly, relatively high towers have to be built from heavier sections having larger cross sections, while the towers of rotary tower cranes used only for small tower heights use tower sections of smaller cross section.

In view of the above, it becomes clear that at least two sets of tower sections of different cross-sectional size must be available and kept in stock. Even if this may not be necessary at the specific building site or the specific place of use of the rotary tower crane, nevertheless, such a supply of tower sections of different cross-sectional size must be kept available at a central storage place.

SUMMARY OF THE INVENTION In order to overcome the problem of using different sized sections to construct crane towers having different cross sections, depending upon the height of the freestanding tower, the present invention sets forth a rotary tower crane whose tower is constructed from vertically aligned rectangular sections whose crosssectional dimensions can be altered to provide a tower of small or large cross section, as required. Each tower section is formed from uniformly sized sidewall units which are detachably connected to form the sidewalls of the tower sections. The height or length of each sidewall unit is the height of each tower section. The width of each sidewall unit is equal to, or is some convenient fraction of, the width necessary to form the sidewalls of a crane tower having the minimum cross-sectional area desired. The width of the sides of the tower sections can be expanded to increase the cross-sectional area of the tower by increasing the number of sidewall units detachably fastened together to form the sidewalls of the tower sections. The longitudinal edges of each sidewall unit include flange sections which facilitate joining of adjacent sidewall units in intersecting relationship or in a planar relationship with the assistance of an additional joining adapter. The flange sections at the longitudinal edges of adjoining sidewall units coact to form a strength-increasing structural member.

Accordingly, in view of the above, it is an object of the present invention to provide a rotary tower crane having a tower which can be constructed in different cross-sectional sizes and configurations, using identically sized components to construct the tower.

"Another oject of the present invention is to provide a rotary tower crane which does not require sections of different size in order to produce towers of different height and/or cross-sectional dimension.

It is a further object of the present invention to provide a rotary tower crane which does not require the storage of large quantities of dissimilar structural members for selective use in constructing towers of different length or cross-sectional dimension.

Yet another object of the present invention is to provide a rotary tower crane which is constructed of detachable units which can be easily altered and rearranged to modify the dimensions and/or strength of the tower.

It is still another object of the present invention to provide a rotary tower crane constructed of detachable units which, when assembled, coact to form strengthaugmenting structural members, to thereby increase the strength of the assembled tower.

Other objects and advantages will be apparent from the following description of several embodiments of the invention, and the novel features will be particularly pointed out hereinafter in connection with the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a rotary tower crane built in accordance with the teachings of the present invention.

FIG. 2 is a cross section through an outer tower section of very small cross section for the rotary tower crane of FIG. 1.

FIG. 3 is a cross section through an outer tower section of a larger cross section for the rotary tower crane of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a freestanding rotary tower crane is constructed in fixed position on a base 2 alongside a building 1. The rotary tower crane has a horizontal boom 3 with a crab 4 movable thereon in the longitudinal direction of the boom. The boom is pivoted to the inner tower head 5 rotatably mounted on inner tower 6.

The inner tower head 6 is inserted into the outer tower 7 and can be telescoped down into the outer tower. The tower 7 consists of a plurality of coaxial, vertically aligned, rectangular sections 8, which are detachably connected to each other by any convenient fastening means (not shown), such as bolting along adjacent ends. Each of the planar walls of the outer tower sections 8 are composed of at least one uniformly sized sidewall unit 9, which units are constructed to be easily detachably connected to each other.

For purposes of simplicity and clarity, the same items appearing in more than one figure will be designated by the same number.

Referring to FIGS. 2 and 3, each of the sidewall units 9 consists of a flat, planar central part 10 which can be of latticework form fabricated from structural members welded together. An angle iron 11 extends along each of the longitudinal edges of each sidewall unit and is fixed thereto as, for example, by welding. Each angle iron 11 is connected to the flat central portion 10 of the sidewall unit by a flange 13 which extends perpendicular to the plane of the flat central portion 10 and which flange 13 in turn connects to a flange 12 which lies in a plane parallel to the plane of the flat central portion 10.

The outer tower section 8 shown in FIG. 2 is composed of only four sidewall units 9. This section 8 is, therefore, the smallest diameter which can enclose the corresponding inner tower 6. The inner tower 6 is supported in the outer tower 7 for axial displacement by means of guides (not shown) in the outer tower, which outer tower is composed of the tower sections 8.

The outer tower sections 8 are assembled by detachably connecting the adjacent angle iron 11 of adjacent perpendicular sidewall units 9. As shown in FIG. 2, the angle irons 11 in adjacent perpendicular sidewall units 9 will also be in perpendicular relation to each other, so that perpendicular flanges 13 can be joined to each other and parallel flanges 12 can be joined to each other, thereby forming a hollow box-shaped section 14 which extends longitudinally along each edge of the tower section 8.

The adjacent flanges can be connected by any convenient means (not shown), such as bolting. The four braces 14 extending along the edges of the tower section 8 provide a stiffening function which increases the strength of the structure.

When the freestanding height of the tower becomes so high that the cross-sectional dimensions of the tower must be increased to provide greater strength and stability, then the cross-sectional dimension of the sections of the tower can be expanded by making the sidewalls of each section from more than one sidewall unit.

FIG. 3 shows an outer tower section 8' of enlarged cross section which is formed from eight sidewall units 9, with each side of the enlarged tower section 8' being formed from two sidewall units 9 lying in the same each other by means of an adapter 16 having a U-.

shaped cross section which fits against the adjacent perpendicular flanges 13 of the adjoining angle irons 1 l in the central portion of the side formed by the two sidewall units. The connection at the edges of the enlarged tower section 8' between the adjacent perpendicular sidewall units 9 is the same as that discussed above in FIG. 2. The structure formed by connecting the adapter 16 to the perpendicular flanges 13 is also a fairly stiff structural member. This member could be further stiffened by connecting the adjacent parallel flanges to form a closed box.

The inner tower 6 shown in FIG. 3 is supported in outer tower 7, which is composed of enlarged sections 8, to allow for axial displacement within tower 7 by means of guides (not shown) in the outer tower 7.

From the above, it should be clear that the use of sidewall units 9 to fabricate tower sections such as those shown in FIGS. 2 and 3 furnishes a high degree of flexibility in the construction of the towers for rotary tower cranes.

For example, in rotary tower cranes having relatively high freestanding towers, the outer tower 7 can be formed completely of enlarged tower sections 8, such as those shown in FIG. 3, or the tower can be formed with even more than two sidewall units 9 forming each side of the tower section.

Similarly, the outer tower 7 may consist of tower sections of varying cross-sectional size with, for example, narrow tower sections 8 in the upper portion of the outer tower and enlarged tower sections in the lower portion of the outer tower. In such instances, transition sections, not shown herein, would be inserted between the narrow and the enlarged tower sections.

Further, although FIG. 2 shows a narrow tower section in which each sidewall unit is approximately equal to the minimum width necessary to enclose the inner tower, it should be apparent that the sidewall units could be made in widths which are convenient fractions of the minimum width for the outer tower section. So, for example, in FIG. 2, each of the walls of tower section 8 could be formed from two relatively narrow sidewall units which, when assembled, would fit closely about inner tower 6. When tower sections using a narrow sidewall unit are sought to be expanded, they would then not need to be doubled in sizein the manner shown for section 8' in FIG. 3, but could be increased in smaller increments.

Although the embodiments of the invention described herein have been shown as rectangular tower sections, it should, of course, be clear that triangular tower sections could also be formed using sidewall units, as could tower sections having cross sections in the form of other standard, geometrical shapes.

It will be understood that various changes in the details, materials and arrangements of parts which have been herein described and illustrated in order to explain the nature of the invention may be made by those skilled in the art within the principle and scope of the invention, as expressed in the appended claims.

What is-claimed is:

1. A rotary tower crane having a tower formed from a plurality of axially aligned tower sections each of said tower sections comprising:

a plurality of intersecting planar walls;

each of said planar walls of said tower section formed from at least one uniformly sized sidewall unit;

each of said sidewall units including a planar center section and two longitudinal edges;

connecting flange means on each of said longitudinal edges of said sidewall units, said connecting flange means detachably connecting adjacent sidewall units to form tower sections having cross sections of standard, closed, geometric forms; each of said connecting flange means extending the length of said sidewall units and comprising:

first flange means connected to and intersecting said planar section of said sidewall means; second flange means connected with said first flange means and intersecting said first flange means; and

said first flange means and said second flange means on adjacent sidewall units on adjacently intersecting walls of said tower sections coacting to form closed hollow sections.

2. The rotary tower crane according to claim 1, wherein said rotary tower crane further comprises an inner tower and wherein said closed, geometric form formed by said sidewall units in constructed to enclose said inner tower.

3. The rotary tower crane according to claim 1 further comprising adapter means dimensioned to coact with said connecting flange means to enable said connecting flange means from adjacent sidewall units to be detachably connected by conventional fastening means.

4. The rotary tower crane according to claim 3 wherein said first and second connecting flange means of adjacent coplanar sidewall units coact with said adapter means to form substantially closed, hollow sections.

5. The rotary tower crane according to claim 4 wherein said connecting flange means on said longitudinal edges of said sidewall units comprise angle iron means having the first flange means thereof perpendicularly disposed to said planar central part of said sidewall unit, and said second flange means connected to said first flange means and disposed parallel to said planar central part of said sidewall unit.

6. The rotary tower crane according to claim 5 wherein said adapter means comprise U-shaped means adapted to coact with the perpendicular flanges of said angle iron means to connect said adjacent connecting flange means of adjacent coplanar sidewall units.

7. The rotary tower crane according to claim 6, wherein said rotary tower crane further comprises an inner tower and wherein said closed, geometric form formed by said sidewall units is constructed to enclose said inner tower.

8. The rotary tower crane according to claim 1 wherein said connecting flange means on said longitudinal edges of said sidewall units comprise angle iron means having the first flange means thereof perpendicularly disposed to said planar central part of said sidewall unit, and said second flange means connected to said first flange means and disposed parallel to said planar central part of said sidewall unit. 

1. A rotary tower crane having a tower formed from a plurality of axially aligned tower sections each of said tower sections comprising: a plurality of intersecting planar walls; each of said planar walls of said tower section formed from at least one uniformly sized sidewall unit; each of said sidewall units including a planar center section and two longitudinal edges; connecting flange means on each of said longitudinal edges of said sidewall units, said connecting flange means detachably connecting adjacent sidewall units to form tower sections having cross sections of standard, closed, geometric forms; each of said connecting flange means extending the length of said sidewall units and comprising: first flange means connected to and intersecting said planar section of said sidewall means; second flange means connected with said first flange means and intersecting said first flange means; and said first flange means and said second flange means on adjacent sidewall units on adjacently intersecting walls of said tower sections coacting to form closed hollow sections.
 2. The rotary tower crane according to claim 1, wherein said rotary tower crane further comprises an inner tower and wherein said closed, geometric form formed by said sidewall units in constructed to enclose said inner tower.
 3. The rotary tower crane according to claim 1 further comprising adapter means dimensioned to coact with said connecting flange means to enable said connecting flange means from adjacent sidewall units to be detachably connected by conventional fastening meaNs.
 4. The rotary tower crane according to claim 3 wherein said first and second connecting flange means of adjacent coplanar sidewall units coact with said adapter means to form substantially closed, hollow sections.
 5. The rotary tower crane according to claim 4 wherein said connecting flange means on said longitudinal edges of said sidewall units comprise angle iron means having the first flange means thereof perpendicularly disposed to said planar central part of said sidewall unit, and said second flange means connected to said first flange means and disposed parallel to said planar central part of said sidewall unit.
 6. The rotary tower crane according to claim 5 wherein said adapter means comprise U-shaped means adapted to coact with the perpendicular flanges of said angle iron means to connect said adjacent connecting flange means of adjacent coplanar sidewall units.
 7. The rotary tower crane according to claim 6, wherein said rotary tower crane further comprises an inner tower and wherein said closed, geometric form formed by said sidewall units is constructed to enclose said inner tower.
 8. The rotary tower crane according to claim 1 wherein said connecting flange means on said longitudinal edges of said sidewall units comprise angle iron means having the first flange means thereof perpendicularly disposed to said planar central part of said sidewall unit, and said second flange means connected to said first flange means and disposed parallel to said planar central part of said sidewall unit. 